Ground Speed in a Track

[Megatron 0]

What is a typical ground speed in a good track? Assuming winds aloft are negligible.

[JohnMitchell 16]

I'll throw out an approximate answer of 60+ mph. When a good jumper does a great track, they create enough lift with their body to have fall rates drop from 110-120 down to the low 80's. At this point, a 1:1 glide ratio would give you a forward speed in the low 80's, with a true airpeed around 110-120 mph. I've seen 1:1 glide ratio quoted for a great track, but I don't know if I believe it. A protrack and GPS could be combined to prove/disprove this.

Anyone got some hard data to back up or correct my estimates?

[SethInMI 174]

On www.trackingderby.com you can see GPS tracks of trackers, both wingsuit and "regular" suit.

By viewing individual performances, you can see the ground speed, vertical speeds, etc. Don't know if they had a tailwind of course, but the ground speeds for the records are 150mph+.

For a typical good track? I don't know.

It's flare not flair, brakes not breaks, bridle not bridal, "could NOT care less" not "could care less".

[jumpwally 0]

Very early on while being taught how to track , i ended up over Rt. 30 at Hinckley, ill and in my track i was gaining and passing the cars going 55. To this day it remains as one of my favorite memories.....

smile, be nice, enjoy life
FB # - 1083

[hackish 8]

I was playing with some GPS hardware and recorded 100km/h (63mph) unfortunately it didn't have a very good fix on the sats so I can't say how accurate it really was.

-Michael

[GaryRay 0]

i tracked with sudsyfist, he said we went really fast...i agreed with him.

JewBag.
www.jewbag.wordpress.com

[d123 4]

I'm more curious on how can I improve my tracking skills? Any pointers are highly appreciated!

Lock, Dock and Two Smoking Barrelrolls!

[fasted3 0]

Practice. Solos are good, groups are better.
Coaching - with video.
Practice some more.
Do tricks. Backfly.
For safety:
Know the flight plan and follow it.
Inform others on the load, including the pilot.
Carry a cell phone.
Tracking is fun. Be careful.
My guess is 80 mph ground speed with no wind and a regular jumpsuit.

But what do I know?

[jakee 1,594]

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Practice. Solos are good, groups are better.

For practicing max tracking, group jumps are generally rubbish.

Do you want to have an ideagasm?

[JohnMitchell 16]

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For practicing max tracking, group jumps are generally rubbish.

I've got to agree with that statement. It's a rare rabbit that challenges me on a tracking dive.

Most people don't track as well as they should or could. That's too bad, because it is a huge survival skill.

The best way to learn to track is getting coaching and practice on the ground on how to do it correctly, then getting video of your max track. Once you start learning to do it right, you can feel the difference when you really hit it.

[JohnMitchell 16]

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I'm more curious on how can I improve my tracking skills? Any pointers are highly appreciated!

The biggest mistake I see on tracking is laziness. To do a good track, you have to push hard on the air if you want it to push you hard across the sky. A good max track position is as follows:

-Legs out straight and knees locked, toes pointed, feet 12 inches apart or less.
-Arms straight, held alongside the body and thighs, palms forward (towards the ground).
-Torso flat, not arched, shoulders cupped forward slightly. A slight bend forward at the waist seems to add just a little more speed sometimes.

You should feel like you are pushing hard on everything to hold this position. I see many tracking with their knees bent, lower legs spilling air, or their arms splayed behind them, spilling more air, or their backs arched, fighting their forward drive. If your legs aren't locked straight, you're not tracking, If your hands aren't next to your body, pushing on the air, you're not tracking. If you have your usual arch in your back, you're not tracking.

I like to coach people on the ground by having them stand in their track position, stand on tip toe, and then, as I push back on their palms, have them lean forward a few inches, until they are really pushing their hands forward, against mine, to keep their arms at their side. This helps them learn the feel of pushing their legs and toes out while pushing their arms down.

There are variations in technique, and many that can out track me, but these tips should give you a good starting point to refine your track.

[flusspirat 0]

pushing really hard and fighting the air will only improve your freefall time and stall your track.

to really get a nice glide ratio you need speed.
just relax, feel the air and play with it don't fight it.

[kallend 2,146]

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pushing really hard and fighting the air will only improve your freefall time and stall your track.

to really get a nice glide ratio you need speed.
just relax, feel the air and play with it don't fight it.

Disagree. The concept of stalling an object with an aspect ratio of around 0.2 is meaningless.

You HAVE to push hard.

...

The only sure way to survive a canopy collision is not to have one.

[CSpenceFLY 1]

And kick your legs.

[JohnMitchell 16]

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And kick your legs.

and flap your arms.

[JohnMitchell 16]

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pushing really hard and fighting the air will only improve your freefall time and stall your track.

to really get a nice glide ratio you need speed.
just relax, feel the air and play with it don't fight it.

Really, a relaxed track is not a track, it's called a delta, and it's a good way to get down to a formation below and in front of you. Your fall rate goes up, but you don't move forward very quickly. It's not a good way to achieve maximum separation from other jumpers when it's time to break off.

I understand when you say "don't fight it." There is a proper body position for good tracking, and it requires you to push on the air. As always, you want to be smooth and in control, not spastic and over amping. It's like skiing powder snow. You have to work at it, but it's a fluid medium, so you need to have body awareness so you can use proper technique.

[kallend 2,146]

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pushing really hard and fighting the air will only improve your freefall time and stall your track.

to really get a nice glide ratio you need speed.
just relax, feel the air and play with it don't fight it.

Really, a relaxed track is not a track, it's called a delta, and it's a good way to get down to a formation below and in front of you. Your fall rate goes up, but you don't move forward very quickly. It's not a good way to achieve maximum separation from other jumpers when it's time to break off.

I understand when you say "don't fight it." There is a proper body position for good tracking, and it requires you to push on the air. As always, you want to be smooth and in control, not spastic and over amping. It's like skiing powder snow. You have to work at it, but it's a fluid medium, so you need to have body awareness so you can use proper technique.

Newton's 3rd law. The air can't push on you unless you push on the air.

...

The only sure way to survive a canopy collision is not to have one.

[d123 4]

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pushing really hard and fighting the air will only improve your freefall time and stall your track.

to really get a nice glide ratio you need speed.
just relax, feel the air and play with it don't fight it.

Really, a relaxed track is not a track, it's called a delta, and it's a good way to get down to a formation below and in front of you. Your fall rate goes up, but you don't move forward very quickly. It's not a good way to achieve maximum separation from other jumpers when it's time to break off.

I understand when you say "don't fight it." There is a proper body position for good tracking, and it requires you to push on the air. As always, you want to be smooth and in control, not spastic and over amping. It's like skiing powder snow. You have to work at it, but it's a fluid medium, so you need to have body awareness so you can use proper technique.

Newton's 3rd law. The air can't push on you unless you push on the air.

I just like better the "ridding powder" analogy

Plus, one (semantic nazi) can argue that no matter how relaxed or tense you are (pushing or no pushing) the air is always going to push on you.

But I do get your point!

Lock, Dock and Two Smoking Barrelrolls!

[flusspirat 0]

just throwing in newton's "lex tertia" may sound pretty scientific, but it doesn't really help here if you have a closer look. you can push as hard as you want, even flap if you think it helps, there are still some more things to consider.

have a look at the second one (impulse) for example.

plus, don't forget bernoulli and his nerdy-friends.

the basic aerodynamic articles on the phoenix-fly page are a good read to start if you are interested in how it works.

[kallend 2,146]

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just throwing in newton's "lex tertia" may sound pretty scientific, but it doesn't really help here if you have a closer look. you can push as hard as you want,

No, you cannot push as hard as you want. You can only push as hard as the air can push back on you.

...

The only sure way to survive a canopy collision is not to have one.

[Arvoitus 1]

Last friday I bought this fancy heart rate monitor which has a GPS sensor accessory. I tried to see what kind of ground speed I could get in a track. I only did one attempt from about 1800 meters and stopped the track at around 1200 meters so I couldn't get a very good acceleration. Also the suit I wore is a fairly tight fit so I can't get much help from it. The speed topped at only 77.4 kmh but I kind of want to believe I did better since the GPS seems to have some sort of a delay at least when you're decelerating. Attached is picture of a HR/alt./speed graph and a picture of the suit I wore.

Your rights end where my feelings begin.

[JohnMitchell 16]

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just throwing in newton's "lex tertia" may sound pretty scientific, but it doesn't really help here if you have a closer look. you can push as hard as you want, even flap if you think it helps, there are still some more things to consider.

Nope, I'm saying Professor Kallend is right, as usual. You have to push on the air to get a desired reaction. Push any harder than you should, and you just touch your toes in freefall. That's the simple truth. And it's the 3rd law that tells us why it works.

I'll also say Bernoulli isn't the effect so much as vortex lift (high alpha, low aspect ratio) and plain old deflection of the airstream.

http://oea.larc.nasa.gov/PAIS/Partners/graphics/FA_18/fig08.jpg

[flusspirat 0]

wow, actually we are on the same side here.

still 2nd is more appropriate (low speed high mass or high speed low mass deflection necessary).

i agree on the vortex theory (there is a nice video to support it on www.pressurized.at).

the problem i have with telling newbies to "push hard" is that almost all of them go out, try to fight the air and use their arms as airbrakes. they do muuuuuch better once they relax and focus on speed.

oh, and i am still convinced that you can stall a track (just like you can stall the f18 in the picture).

[JohnMitchell 16]

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the problem i have with telling newbies to "push hard" is that almost all of them go out, try to fight the air and use their arms as airbrakes. they do muuuuuch better once they relax and focus on speed.

oh, and i am still convinced that you can stall a track (just like you can stall the f18 in the picture).

Yes, in training, people learn 10% by listening, 90% by doing. That is why I physically teach the body position and muscle tension required. From an earlier post:

I like to coach people on the ground by having them stand in their track position, stand on tip toe, and then, as I push back on their palms, have them lean forward a few inches, until they are really pushing their hands forward, against mine, to keep their arms at their side. This helps them learn the feel of pushing their legs and toes out while pushing their arms down.


I've had some success with this method of ground training. It gives them the feel of what they should be doing.


I agree, too, that a track can be stalled, but it would be to poor technique, and wouldn't be easy to do consistently. It so easy to do a good track once you learn how.